Saturday, May 17, 2008

Fitness Rsearch for May 2008

Some fitness news you can use.

May 15, 2008
Exercise ETC's Review of Exercise Related Research

Compiled by Chris Marino, MS, CSCS
Director of Education, Exercise ETC

Increased Muscularity Results in Stronger Bones

Hip fractures present one of the greatest concerns for people with Osteoporosis. The latest statistics show that 25% of women over 50 who suffer a hip fracture die within 1 year. Exercise has long been shown to help reduce the risk of hip fractures by increasing bone mineral density while improving core strength and balance.

A recent study suggests that women might also want to pack on the muscle. Researchers at the University of Iowa reported that lower-body muscle mass was a better predictor of hipbone mineral density than either strength or physical activity level.

Fifteen hundred men and women over age 50 were evaluated for quadriceps strength and lower-body muscle mass. Although hip BMD and quadricep strength were related, the relationship was not consistent. The relationship between lower-body muscle mass and Hip BMD was maintained even after age, race, and sex were accounted for.

A simple method for identifying individuals at increased risk for a hip fracture can help reduce the mortality associated with Osteoporosis. This study provides insight into such a method. In addition, exercise professionals should rethink program design for older clients to include improvements in both lower body muscle mass and strength for osteoporosis patients.

Segal, N.A. et al (2008) Muscle Mass Is More Strongly Related to Hip Bone Mineral Density Than Is Quadriceps Strength or Lower Activity Level in Adults Over Age 50 Year. Journal of Clinical Densitomitry.

Can Walnuts Help to Prevent Prostate Cancer & Heart Disease?

Walnuts are not only one of the best sources of plant protein, but are also an excellent source of Omega-3 Fatty Acids and Vitamin E, a fat-soluble antioxidant. Considerable research has shown the value of Omega-3 fatty acids and antioxidants in the prevention of many diseases. Now, researchers have found that walnuts my reduce the risk of prostate cancer and improve vascular health.

Researchers supplemented the diets of 21 older men with walnuts for 8-weeks. Levels of Vitamin E and prostate specific androgens (PSAs) were measured before and after.

Subjects consumed their typical diet with or without a 75g/day walnut supplement. Five participants completed a timed study to determine acute changes in triglyceride levels in the blood. Measurements were taken at baseline and 1, 2, 4 and 8 hours after eating 75g of walnuts.

The results showed a significant decrease in triglycerides, which may reduce the risk of heart disease and a trend towards a decrease in PSA levels, which may reduce the risk of prostate cancer.

This research also supports previous findings that walnuts may help reduce inflammation, decrease risk of certain types of cancer and reduce risk or delay the onset of Alzheimer's disease.

Spaccarotella, K.J. et al (2008) The effect of walnut intake on factors related to prostate and vascular health in older men. Nutrition Journal.

The Financial Burden of Obesity in the Elderly

One of the greatest challenges for America in the 21st Century will be funding healthcare for older adults who rely on Medicare and Medicaid. In fact, economists predict that at the current rate Medicare/Medicaid will be bankrupt by 2030.

By 2010 approximately 70% of the American population, many of whom will be over 65, will be overweight or obese. It is rarely disputed that the obesity epidemic has contributed to the instability of the American health care system.

A recent study examined the contribution of overweight and obesity to the current financial strain experienced by the US Healthcare System. Researchers at the University of Florida used body weight data to compare lifetime health care expenditures for older Americans over the age of 65.

Compared to normal weight men, men who were overweight or obese at age 65 up to 13% more on health care than normal weight men. Overweight or obese women had expenditures that were 11 to 17% higher than normal weight comparisons.

This research supports the initiative to reduce health care costs by making concerted behavioral such as eating a little less and exercising a little more.

Yang, Z., and Hall, A.G. (2008) The Financial Burden of Overweight and Obesity among Elderly Americans: The Dynamics of Weight, Longevity, and Health Care Cost. Health Services Research. 43(3):849-68.

Maximal Strength Training Improves Running Economy

Researchers from Norway have strengthened the ties between maximal strength training and running economy. Running economy is one of three components essential to performing well, the other two being maximal oxygen consumption and lactate threshold.

Well-trained male and female runners either participated in strength training 3 times per week for 8-weeks or served as controls. The strength training group performed 4 sets of 4 repetition maximum (RM) half-squats. Both groups completed their normal endurance training routines.

The strength training group increased their 1RM in the half-squat by 33.2%. Their rate of force development increased by 26%, their running economy improved by 5%, and their time to exhaustion at maximal aerobic speed improved by 21.3%. VO2max and bodyweight remained unchanged.

Because endurance activities are mostly dependent on aerobic metabolism it would seem to make sense to think that performance would be determined by training the aerobic energy systems. However, the ability to produce joint actions at submaximal intensities, as in running, is related to maximal strength. This study has supported the need for strength training in the runner and has also found that running does not interfere with the ability to gain strength.

Storen, O. et al (2008) Maximal Strength Training Improves Running Economy in Distance Runners. Medicine and Science in Sports and Exercise. May 2. (ePub ahead of print)

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